As replied earlier, we tested and realized we can do much better by dripping it from top instead of the mist. We will also be doing flood-n-flush kinda method in the much bigger setup. Cleaning was one thing we learned the hard way and so the reason for our modified method.

We will still be using mist spray method with other crops that has less dense rooting, etc.

You could... detect pressure build up -> assume clogged

set pressure 0

open a solenoid connected to h2o2 with enough elevation to reach the clog

detect flow increase ->assume unclogged

close solenoid, set pressure 50 psi (or whatever)

This might best be done with a hydraulic circuit rather than electronic sensors, by the way. Ie. to detect pressure build up have a secondary line with slight resistance before the nozzle that when pressurized triggers other hydraulic elements which cut pressure, etc.